SOLUTION: In class homework im completely lost help is needed very urgently Thanks A video game store sells video games for $30 each. The store has a coupon for $9 off the total purchase f

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Question 726864: In class homework im completely lost help is needed very urgently
Thanks
A video game store sells video games for $30 each. The store has a coupon for $9 off the total purchase for up to 10 games.
a) Determine the equation and graph the function that describes the relationship between the total cost and the number of video games a customer buys.
(just need help with equation),
and state domain and range

Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
Help with the formula:
Let n = how many video games being purchased for a total purchase.
$30/game and letting p = purchase value including the applied savings deal, p=30n-9n.

The description also includes restrictions making effect on the domain for p.
n is a natural number between 1 and 10 inclusive.

CONTINUED ANSWER DISCUSIION
Although developed as if to be a linear equation, this problem really describes an Arithmetic sequence. The first term is 30-9=21, and the common difference among neighboring terms is (60-18)-21=21. The sequence is also finite, since the terms are 21, 42,63, 84, 105, 126, 147, 168, 189, 210. 21 is for n=1 and 210 is for n=10. These are ten specific points which fit on a line, but they are still ten specific points and they may be graphed as functions of the natural number between 1 and 10 inclusive.